Manufacture of match splints



May25, 1965 R. N. BERRY MANUFACTURE OF MATCH SPLINTS Filed Feb. 20, 1962 INVENTOR BY \4-L3 Hoops ATTORNEY an- I t a s Pa 3,185,552 MANUFACTURE OF MATCH SPLINTS Roger N. Berry, Stamford, Conn., assignor to Diamond International Corporation, a corporation of Delaware .Filed Feb. 20, 1962,.Ser. No. 174,497

. 12 Claims. (CI. 44-42) This invention relates to the manufacture of paper match splints, and more particularly to methods of mak- The present application is a continuation-in-part of applicants co-pending application Serial No. 798,697, filed March 11', 1959, now abandoned.

In the manufacture of paper book matches, which comprise a plurality of match splints made of cardboard or hard paper, usually arranged in two parallel rows, projecting from an integral narrow marginal strip to which is stapled a foldable flexible paper safety cover flap, the material of which the match splints has been made has usually been ordinary fibrous pulp board or paper modified by the addition of minor percentage of certain coloring and sizing agents. It has been, and still is, customary to manufacture the cardboard material from which the match splints are cut by continuously forming elongated Webs at a paper making mill, and shipping such webs in rolled up form to the match making plant. There the splints are formed by subjecting the Webs to the cutting action of a punch press, or the like, to produce what is known in the trade as combs, each of which consists of an elongated marginal strip from which about 100* splints may project. The outer free ends of such splintsare each provided with a pyrotechnic head, adapted to be ignited by striking it against a fulminating friction surface mounted on the safety cover flap. It has also been customary to coat the splints for a portion of their length with a readily combustible material, such as paraffin, prior to the application of the pyrotechnic headythereto, in order to render the splint capable of transmitting a flame from the ignitable tip to the body of the splint. Finally, the subdivided combs of dipped splints are stapled to their cover flaps.

Paper book matches have become quite popular, and to a large extent they have supplanted conventional boxed wooden matches in recent years. Yet, it is generally recognized that for some purposes the wooden matches offer advantages over ordinary paper match splints, in that the wooden splints are considerably stifier and stronger than the paper splints, and in particular the wooden splints exhibit a greater breaking strength. Sometimes the paper splints may become broken or badly bent while being separated from the marginal strip, or while being ignited on the frictional striking, surface, which may create a.

danger of burning the users fingers. On the other hand, wooden matches are much more expensive to manufacture than are paper match books, and the wooden matches cannot economically be put into a convenient book form.

The natural stiffness of wooden match splints enables them to be used for other purposes, which may appeal to some users, such as cleaning fingernails, picking teeth, etc. The lack of such stiffness in ordinary paper match splints may sometimes interfere with their intended primary purpose of providing a flame, since they cannot withstand being carried in a pocket or purse for several days wherein they may be joggled against other objects, such as keys, etc., without destroying their usefulness for ignition purposes. Consequently, it is desirable to increase the durability and stiffness of paper match splints in order to impart thereto the primary advantages of Patented May 25, 1965 7 wooden match splints, while maintaining the convenience, low-cost and ease of manufacture of the paper match splints.

lit has frequently been proposed to coat or impregnate paper match splints with a plastic or resinous composition to impart increased stiffness thereto, but no entirely satisfactory method has been known heretofore for accomplishing this purpose. Over a period of many years, numerous comparative experiments have been conducted in an eliort to improve the quality of paper match splints. For example, efforts have been made to alter the acidity of the beater furnish and the nature of the sizing agent added thereto at the paper mill. Attempts have been made to coat or impregnate the cut splints with special starches, gums and resins in a separate operation. Efforts have also been made to incorporate various stiffening resins into the beater furnish at the paper making mill, but in every instance the webs produced therefrom became considerably stiifened during drying of the Webs, and such stiffness of the webs interfered with or made it impossible to roll up the webs for shipment to the match making plant. Furthermore, it was found that the cutting equipment at the match making plant was incapable of cleanly and elfectively cutting combs from the stiffened webs. Hence, these prior experiments failed to produce any outstanding improvement in the paper match splints.

An object of the present invention is to provide new and improved methods of manufacturing paper match splints.

Another object of the invention is to provide new and improved methods of making resin impregnated paper match splits for improving the durability, stiffness and burning characteristics of such splints.

Still another object of the invention is to provide new and improved methods of making paper book matches having paper match splints characterized by improved durability and breaking strength equivalent to that of wooden match splints.

Other objects and the nature and advantages of the instant invention will be apparent from the following detailed description, taken in conjunction with the accompanying drawing, wherein:

FIG. 1 is a perspective view of a paper match book provided with a plurality of paper match splints which have been produced by methods embodying the present invention;

FIG. 2 is a side elevation view of a comb of paper match splints utilized at one stage of the manufacture of the match book shown in FIG. 1, and

. FIG, 3 is an enlarged detailed vertical sectional view 1 of a single paper match splint produced by methods emsplints are subsequently cut at the match making plant' or by impregnating the web with the resin after it has been formed. In the former case, the resin is uniformly distributed or dispersed throughout the dilute liquid pulp slurry constituting the beater furnish in an amount sufficient to result in the desired percentage of resin in the final match splint. It will be appreciated that a higher percentage in the form of an extra quantity of resin must be included in the beater furnish to compensate from normal drainage losses in the white water.

The paperboard webs are manufactured in the usual manner by suction deposition on cylinder type paper making machines, or the like, and the webs are then dried at relatively low temperatures. For the purposes of the present invention, it is particularly important that the resin impregnated paperboard webs be dried without effecting fusing or curing of the resin. Hence, resins having relatively high curing or fusing temperatures are employed, and any heat applied to dry the webs at the paper making mill must be at temperatures substantially below the curing or fusing temperatures of the resins. The fusing or curing temperature of the stiffening resin must be above the drying temperature of the paper, that is, above the boiling point of water, and yet below the carbonization temperature of the paper, about 350 F. Thus, the fusing or curing temperature of the resin should preferably be in the approximate range of 225-350 F. The dried resin impregnated paperboard webs, which are still relatively soft and pliable due to the fact that the resin therein remains refused or uncured, are rolled up for shipment from the paper mill to the match plant, where they are unrolled and subject to the usual cutting operation to form combs of match splints.

When the impregnation method is used, the paperboard web is impregnated with the resin and then dried at a temperature below the curing or fusing temperature of the resin used.

Stiifening of the resin impregnating the match splints takes place only after the splints have been cut from the webs. The stifiening is accomplished by a heat treatment of relatively short duration and in which in the case of polymerizable or thermosetting resins causes completion of curing thereof, and in the case of thermoplastic resins causes fusion of the resins, and bonding thereof to the pulp fibers. In some cases the heat treatment may be accompanied by the pressure treament. It is contemplated that the heat treatment will be appropriate for the nature of the resin. Thus, the stiffening by heat treatment results in a fusion with subsequent solidification when thermoplastic resins are used and a curing of polymerization when thermosetting resins are used.

Various resins may be employed in methods embodying the invention, and either thermoplastic or thermosetting heat curable resins are considered suitable so long as the curing or fusing temperature is in the range indicated above. It may also be possible to incorporate monomeric or incompletely polymerized resins into the beater furnish, and to complete the polymerization of such resins after the cutting of the match splints from the paperboard webs at the match plant.

Thermoplastic resins which may be used are those which have a melting point in the range of 225-350 F. Examples include Vinsol resin, polyethyleues, polypropylenes, and the like.

Vinsol resin, which is delivered from southern pine wood, is dark-colored, and is a complexe mixture of various chemical components. It is manufactured in accordance with the Hall Patent 2,193,026 and its properties and uses are described in a publication of the Hercules Powder Company entitled Vinsol Resin, Properties and Uses, copyright 1958, identified on the last page as Form 400- 567. Vinsol resin has a methoxy content of about 36% as distinguished from gum rosin which has a methoxy content of 0.10.2% and oxidized wood gum which has a methoxy content of 0.3-0.4%. Vinsol is made from the aliphatic hydrocarbon-insoluble solid portion of the pine wood extract. Its constituents include acidic phenolic materials in the form of high molecular weight phenols, carboxyl-substituted phenols, substituted phenyl ethers, and poly-phenols. It contains acidic materials derived from resin acids and oxidized resin acids. High molecular weight neutral compounds are present, apparently derived from resinous and polymerized terpenes. Some wax is also present. The exact composition of Vinsol and the structure of each constituent are not entirely known, but

the following table gives the classes of material and their approximate concentration:

Composition of Vinsol Vinsol is insoluble in light petroleum hydrocarbons and soluble in alcohol. The average softening point of Vinsol is about 240 F. and it has an average molecular weight of 470.

Vinsol resin will be referred to hereafter in the claims as a substantially petroleum hydrocarbon insoluble pine wood resin.

Thermosetting resins may also be used such as the phenolic resins including phenol-formaldehyde resin, ureaforrnaldehyde resin and melamine-formaldehyde resin, also epoxy resins and others which have a curing temperature in the range of 2 25350 F.

The amount of stiffening resin which is added can vary from 5-35% per weight of the paper in the finished product.

In the usual manner, the cut match splints are dipped into a suitable well-known pyrotechnic composition to apply ignitable heads thereto, and such pyrotechnic heads are then dried by a controlled heat treatment. In recent years such heads have customarily been dried by electronic heaters operating on dielectric principles.

The stiffening of the resin impregnating the splint may be performed immediately after cutting the splints from the uncured paperboard web, and prior to the dipping operation in which the pyrotechnic heads are formed, or a single heat treatment may be utilized to effect simultaneously the curing or fusing of the resin and the drying of the pyrotechnic heads. Since the resins employed are non-conductive polar compounds, they are affected by dielectric heating, and hence the resins may be cured or fused in this manner during drying of the pyrotechnic heads. Resort to a single heat treating operation for simultaneously curing or fusing the resins and drying the pyrotechnic heads on the match splint, obviously simplifies the process by reducing the number of steps required.

The resins employed are preferably readily combustible so that they may serve to transmit the flame from the ignitable tip of the match splints to the body portion thereof. It is also desirable that the resins selected should burn without creating excesive soot or obnoxious odors. Thus, by manufacturing paper match splints in accordance with methods embodying the pereseut invention, the need is eliminated for the paraffin dipping operation formerly employed for ordinary match splints. Another important advantage offered by methods embodying the invention is that any scrap or waste paperboard web from the splint cutting operation at the match plant, which is still relatively soft and pliable because it contains uncured or unfused impregnating resin, may be shipped back to the paper making mill and be added directly to the beater furnish of the pulp stock.

Referring to the drawings, FIG. 1 shows a plurality of paper match splints 10 assembled in book form and attached at their base by means of staples 12 to a foldable paper cover flap 14 having an outer free end 16 adapted to be tucked downwardly behind an upturned stapled lower end 18 of the cover flap 14 when it is closed.

FIG. 2 shows the appearance of a unit of a comb of match splints immediately following the cutting operation. This unit includes a plurality of parallel splints projecting up wardly from a narrow marginal base 22. In FIG. 3 there is shown a representative type of a single paper match splint 30 produced by methods embodying the invention,

and having a pyrotechnic head 32. a

The body of the splint 30 is laminate in construction, and it includes a pair of outer liner layers 34 secured to an intermediate filler layer 36. A high quality grade of pulp stock possibly containing suitable coloring agents may be used to form the outer liner layers 34, in order to give a fine appearance in the finished match splint, while ordinary cheaper grades of pulp stock may be used to form the inner filler layer 36. The paperboard web from which such splints are cut may be made in this composite laminate form of filler layers and liner layers at the paper making mill by well known methods, using two different pulp slurries to form the different layers of the splint. It should be understood that while it is preferred to utilize a laminate construction for the splints, it is also contemplated that ordinary homogeneous single ply structures are acceptable for making paper match splints.

Resin impregnation may be confined to the outer liner layers 34, or both these liner layers and the inner filler layer 36 may be impregnated, if desired. However, it has been determined by comparison experimentation that the greatest benefits are obtained from the presence of the resin in the liner layers rather than in the filler layer, even though the liner layers 34 may together constitute only about A; the total weight of the composite splint body. In this instance, the liner layers preferably contain from about 5% up to about 35 by Weight of resin. The filler layer 36 may contain the same percentage of resin as is in the liner layers 34,0rthefiller layer 36 may contain a smaller percentage of the resin. However, the; filler layer 36 need not necessarily contain any resin provided suflicient resin is present in the liner layers 34. The resultant percentage of resin present in the composite liner layers 34 and filler layer 36 may range from about 5% up to about 35% by weight, and the preferred range is from about to about 25% by weight.

The final heat treatment of the impregnating resin may be accomplished in any appropriate manner, as has been previously indicated. Electronic dielectric ovens may be employed, or infra-red lamp heats, or simply a heated gaseous atmosphere.

When the modified rosin known by the tradename Vinsol was used as the impregnating resin, it was found that heating of the impregnated splints at a temperature of 225 F. to about 250 F. for about 16 minutes was effective to achieve fusion thereof. It was found that the resultant resin impregnated paper match splints exhibited a substantial increase in breaking strength over ordinary untreated paper splints, accompanied by a desirable improvement in burning characteristics without requiring the customary parafiin dip treatment for that purpose.

When a phenolic resin is used as the impregnating resin, the paperboard may be dipped into the phenolic varnish followed by drying which converts the resin to the B stage.

At this stage, the impregnated paper is pliable and can be rolled and slit as desired. After the slitting operation, the resin can be cured to its final stiff state by heat and/ or pressure, for example by the use of heated rolls.

Approximately 20-30% of solid resin of the weight of paper has been found to yield a match stick which will snap rather than bend after the curing to its final state.

Methods embodying the present invention provide a highly economical and rapid system for the mass production of superior paper match splints. It is evident that the principles of the invention are peculiarly applicable to the production of match splints, but the invention may be applied successfully in the production of other paper or molded pulp articles, wherein such articles are made 6 from a molded web which is dried before the articles are cut therefrom and subsequently subjected to a heat treatment for drying or other purposes.

It will be obvious to those skilled in the art that various changes may be made, without departing from the spirit of the invention, and therefore the invention is not limited to what is shown in the drawing and described in the specification but only as indicated in the appended claims.

What is claimed is:

l. A method of making stiffening resin impregnated paper match splints, comprising the steps of uniformly incorporating a predetermined percentage of a stifiening resin into a beater furnish of dilute liquid pulp slurry, said resin being selected from the group consisting of thermoplastic resins having a melting point in the range of 225-350 F. and thermosetting resi-ns which are curable by heating to the range of 225350 F., said percentage of resin being sufiicient eventually to produce from such slurry splints containing about 5% to about 35% by weight of impregnating resin, forming a continuous web of resin impregnated paperboard from such slurry, drying the web by heating it at a temperature below 225 F. until a pliable dried web is formed, cutting the dried web to form a plurality of resin impregnated paper match splints therefrom, and then heating the splints at a temperature in the range of 225350 F. until the resin cures thereby stiifening the resin impregnated paper match splints.

2. A method of making stiflening resin impregnated paper match splints, comprising the steps of dipping a web of paperboard into a bath of a stiifening resin to impregnate said web with a predetermined percentage of said stiffening resin, said resin being selected from the group consisting of thermoplastic resins having a melting point in the range of 225-350" F. and thermosetting resins which are curable by heating to the range of 225- 350 F., said percentage of resin being suflicient eventually to produce paperboard splints containing about 5% to about 35% by weight of impregnating resin, drying the impregnated paperboard web by heating it at a temperature below 225 F. until a pliable dried web is formed, cutting the dried web to form a plurality of resin impregnated'paper match splints therefrom, dipping one end of the splints into a wet pyrotechnic composition to form ignitable heads on the splints, and then heating the splints at a temperature in the range of 225-350 F. until the resin cures. thereby simultaneously stiffening the resin impregnated splints and drying the pyrotechnic composition thereon.

3. A method of making stiffening resin impregnated paper match splints, comprising the steps of uniformly incorporating a predetermined percentage of a stiffening resin into a heater furnish of dilute liquid slurry of a high quality grade of pulp stock, said resin being selected from the group consisting of thermoplastic resins having a melting point in the range of 225-350 F. and thermosetting resins which are curable by heating to the range of 225-350 F., forming a continuous web of resin impregnated paper from such slurry, forming a continuous web of laminated paperboard having outer liner layers composed of said resin impregnated paper and having an intermediate filler layer composed of an ordinary grade of pulp stock, drying the web of laminated paperboard by heating it at a temperature below 225 F. until a pliable dried web is formed, cutting the dried web to form a plurality of resin impregnated laminated paperboard match splints therefrom, and then subjecting the splints to a heat-treatment at a temperature in the range of 225-350 F. until the resin cures thereby stiffening the impregnated splints, said percentage of resin incorporated into the beater furnish being suflicient to produce a resin content in the liner layers of the dried splints of about 5% to about 35% by weight.

4. The method in accordance with claim 1 wherein the stiffening resin is a thermoplastic resin derived from souther pine which is a substantially petroleum hydrocarbon insoluble pine wood resin having a methoxy content of about 3 6%.

5. The method in accordance with claim 3 wherein the stiffening resin is a thermoplastic resin derived from southern pine which is a substantially petroleum hydrocarbon insoluble pi-ne wood resin having a methoxy content of about 36%.

6. The method in accordance with claim 1 wherein the stiffening resin is a phenolic thermosetting resin.

7. The method of making stiffening resin impregnated paper match splints, comprising the steps of dipping a web of paperboard into a bath of a stiffening resin to impregnate said web with a predetermined percentage of said stiffening resin, said resin being selected from the group consisting of thermoplastic resins having a melting point in the range of 225-350 F. and thermosetting resins which are curable by heating to the range of 225- 350 F., said percentage of resin being sufficient to produce paperboard containing in the range of about to 35 by weight of impregnating resin, drying the impregnated paperboard web by heating at a temperature below 225 F. until a pliable dried web is formed, cutting the dried web to form a plurality of resin impregnated paper match splints therefrom, and then heating the splints at a temperature in the range of 225-350" F. until the resin cures thereby stiffening the resin impregnated paper match splints.

8. The method in accordance with claim 7 wherein the stiffening resin is a thermoplastic resin derived from southern pine which is a substantially petroleum hydrocarbon insoluble pine wood resin having a methoxy content of about 36%.

9. The method in accordance with claim 7 wherein the stiffening resin is a phenolic thermosetting resin.

10. A method of making stiffening resin impregnated paper match splints, comprising the steps of uniformly incorporating a predetermined percentage of a stiffening resin into a beater furnish of dilute liquid pulp slurry, said resin being selected from the group consisting of thermoplastic resins having a melting point in the range of 225-350 F. and thermosetting resins which are curable by heating to the range of 225-350 F., said percentage of resin being sufficient eventually to produce from such slurry splints containing about 5% to about 35% by weight of impregnating resin, forming a continuous web of resin impregnated paperboard from such slurry, drying the web by heating it at a temperature below 225 F. until a pliable dried web is formed, cutting the dried web to form a plurality of resin impregnated paper match splints therefrom, dipping one end of the splints into a wet pyrotechnic composition to form ignitable heads on the splints, and then heating the splints at a temperature in the range of 225350 F. until the resin cures, thereby simultaneously stiffening the resin impregnated splints and drying the pyrotechnic composition thereon.

11. A method of making stiffening resin impregnated paper match splints, comprising the steps of dipping a web of paper made of a high quality grade of pulp stock into a bath of a stiffening resin to impregnate said paper with a predetermined percentage of said stiffening resin, said resin being selected from the group consisting of thermoplastic resins having a melting point in the range of 225-350 F. and thermosetting resins which are curable by heating to a range of 225-350 F., said percentage of resin being sufficient eventually to produce a paper web containing about 5% to about 35% by weight of impregnating resin, forming a continuous web of laminated paperboard having outer liner layers composed of said resin impregnated paper and having an intermediate filler layer composed of an ordinary grade of pulp stock, drying the web of laminated paperboard by heating it at a temperature below 225 F. until the pliable dried web is formed, cutting the dried web to form a plurality of resin impregnated laminated paperboard match splints therefrom, and then subjecting the splints to a heat treatment at a temperature in the range of 225350 F. until the resin cures thereby stiffening the impregnated splints.

12. The method in accordance with claim 11 wherein prior to the final heat treatment step the splints are dipped into a wet pyrotechnic composition to form ignitable heads on the splints, and then conducting the final heat treatment operation to simultaneously stiffen the resin impregnated splints and to dry the pyrotechnic composition thereon.

References Cited by the Examiner UNITED STATES PATENTS 1,829,994 11/31 Langley 4444 X 2,495,575 1/50 Ellern 4446 2,503,407 4/50 Perry 162- 180 X 2,601,114 1/52 Gillespie 162124 2,647,048 7/53 Ellern 4446 2,913,356 11/59 Schroeder 162-464 X DANIEL E. WYMAN, Primary Examiner. 

1. A METHOD OF MAKING STIFFENING RESIN IMPREGNATED PAPER MATCH SPLINTS, COMPRISING THE STEPS OF UNIFORMLY INCORPORATING A PREDETERMINED PERCENTAGE OF A STIFFENING RESIN INTO A BEATER FURNISH OF DILUTE LIQUID PULP SLURRY, SAID RESIN BEING SELECTED FROM THE GROUP CONSISTING OF THERMOPLASTIC RESINS HAVING A MELTING POINT IN THE RANGE OF 225-350*F. AND THERMOSETTING RESINS WHICH ARE CURABLE BY HEATING TO THE RANGE OF 225-350*F., SAID PERCENTAGE OF RESIN BEING SUFFICIENT EVENTUALLY TO PRODUCE FROM SUCH SLURRY SPLINTS CONTAINING ABOUT 5% TO ABOUT 35% BY WEIGHT OF IMPREGNATING RESIN, FORMING A CONTINUOUS WEB OF RESIN IMPREGNATED PAPERBOARD FROM SUCH SLURRY, DRYING THE WEB BY HEATING IT AT A TEMPERATURE BELOW 225* F. UNTIL A PLIABLE DRIED WEB IS FORMED, CUTTING THE DRIED WEB TO FORM A PLURALITY OF RESIN IMPREGNATED PAPER MATCH SPLINTS THEREFROM, AND THEN HEATING THE SPLINTS AT A TEMPERATURE IN THE RANGE OF 225-350*F. UNTIL THE RESIN CURES THEREBY STIFFENING THE RESIN IMPREGNATED PAPER MATCH SPLINTS. 